• 한국전산구조공학회:학술대회논문집
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• 한국전산구조공학회 2000년도 가을 학술발표회논문집
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• pp.190-197
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• 2000

A moment-curvature relationship to simulate the behavior of reinforced concrete beam under cyclic loading is introduced. Unlike previous moment-curvature models and the layered section approach, the proposed model takes into consideration the bond-slip effect by using monotonic moment-curvature relationship constructed on the basis of the bond-slip relation and corresponding equilibrium equation at each nodal point. In addition, the use of curved unloading and reloading branches inferred from the stress-strain relation of steel gives more exact numerical result. The advantages of the proposed model, comparing to layered section approach, may be on the reduction in calculation time and memory space in case of its application to large structures. The modification of the moment-curvature relation to reflect the fixed-end rotation and pinching effect is also introduced. Finally, correlation studies between analytical results and experimental studies are conducted to establish the validity of the proposed model.

• Structural Engineering and Mechanics
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• 제54권4호
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• pp.793-807
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• 2015

Constructing the influence lines of forces of statically indeterminate structures is a traditional issue in structural engineering and mechanics. However, the existing kinematic method for establishing these force influence lines is an indirect or mixed approach by combining the force method with the theorem of reciprocal displacements, which is yet inconsistent with the kinematic method for statically determinate structure. This paper proposes the direct kinematic method in conjunction with the load-displacement differential relation for exactly constructing influence lines of reaction and internal forces of indeterminate structures. Firstly, through applying the principle of virtual displacement, the formula for influence lines of reaction and internal forces of indeterminate structure via direct kinematic method is derived based on the released structure. Then, a computational approach with a clear concept and unified procedure as well as wide applicability based on the load-displacement differential relation of beam is suggested to achieve conveniently the closed-form expression of force influence lines, and exactly draw them. Finally, three representative examples for constructing force influence lines of statically indeterminate beams and frame illustrate the superiority of the proposed method.

• 한국전산구조공학회:학술대회논문집
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• 한국전산구조공학회 2002년도 봄 학술발표회 논문집
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• pp.3-11
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• 2002

A moment-curvature relationship to simulate the behavior of reinforced concrete (RC) columns under cyclic loading is introduced. Unlike previous moment-curvature models and the layered section approach, the unposed model takes into account the bond-slip effect by using a monotonic moment-curvature relationship constructed on the basis of the bond-slip relation and corresponding equilibrium equation at each nodal point. In addition, the use of curved unloading and reloading branches inferred from the stress-strain relation of steel gives more exact numerical result. The pinching enact caused by axial force is considered with an assumption that the absorbing energy corresponding to any deformation level maintains constant regardless of the magnitude of applied axial force. The advantages of the proposed model, comparing tn layered section approach, may be on the reduction in calculation time and memory space in case of its application to large structures.. Finally, correlation studies between analytical results and experimental studies are conducted to establish the validity of the proposed mood.

• Structural Engineering and Mechanics
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• 제52권2호
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• pp.239-260
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• 2014

Non-stationary random vibration of linear structures with uncertain parameters is investigated in this paper. A time-domain explicit formulation method is first presented for dynamic response analysis of deterministic structures subjected to non-stationary random excitations. The method is then employed to predict the random responses of a structure with given values of structural parameters, which are used to fit the conditional expectations of responses with relation to the structural random parameters by the response surface technique. Based on the total expectation theorem, the known conditional expectations are averaged to yield the random responses of stochastic structures as the total expectations. A numerical example involving a frame structure is investigated to illustrate the effectiveness of the present approach by comparison with the power spectrum method and the Monte Carlo simulation method. The proposed method is also applied to non-stationary random seismic analysis of a practical arch bridge with structural uncertainties, indicating the feasibility of the present approach for analysis of complex structures.

• 한국문헌정보학회지
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• 제48권3호
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• pp.281-301
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• 2014

본 연구는 민원을 청원과 불만표현의 두 가지 성격을 지닌 행위로 이해하고, 공공도서관에서 민원의 성격을 파악하고 그 요인을 도출하는 것을 목적으로 한다. 이를 위해 이용자와의 도서관 민원에 대한 심층면담과 선행연구를 바탕으로 설문지를 개발하여, 3개 공공도서관의 이용자를 대상으로 설문조사를 실시하고, 수거된 설문지 154부를 바탕으로 요인분석, 정준상관분석 및 회귀분석을 이용하여 통계분석을 실시하였다. 분석결과, 도서관 민원은 건의/청원과 불평행위로 구분하여 이해할 수 있었으며, 이러한 각각의 종속요인에 영향을 미치는 독립요인으로 사서전문성, 서비스편의성, 사서와의 교류 등 6개 요인을 도출하였다. 또한 각각의 종속요인에 대한 개별 독립요인의 영향을 분석함으로써 건의/청원 및 불평행위의 성격은 물론, 민원에 대한 기능적 접근뿐 아니라 구조관계적 접근의 중요성을 파악하였다. 이러한 분석 및 토의를 토대로 종속변수로서의 민원뿐 아니라 도서관 성과에 영향을 미치는 독립변수로서의 민원 및 도서관의 대처에 대한 연구의 필요성을 제시하였다.

• 국제학술발표논문집
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• The 3th International Conference on Construction Engineering and Project Management
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• pp.1223-1230
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• 2009

In the construction industry, Case-Based Reasoning (CBR) is considered to be the most suitable approach and determining the attribute weights is an important CBR problem. In this paper, a method is proposed for determining attribute weights that are calculated with attribute relation. The basic items of consideration were qualitative and quantitative influence factors. These quantitative factors were related to the qualitative factors to develop a Cost Drivers-structural equation model which can be used to estimate construction cost by considering attribute weight. The process of determining the attribute weight-structural equation model consists o 4 phases: selecting the predominant Cost Drivers for the SEM, applying the Cost Driers in the SEM, determining and verifying the attribute weights and deriving the Cost Estimation Equation. This study develops a cost estimating technique that complements the CBR method with a Cost Drivers-structural equation model which can be actively used during the schematic estimating phases of construction.

• 가정과삶의질연구
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• 제10권1호통권19호
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• pp.75-94
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• 1992

The purpose of this study was to provide for the appropriate conflict management strategies to employed wives by investigation casual relations of conflict, resources, home management behavior and managerial satisfaction by applying a system's approach. The data were collected through the questionnaire whose respondent were 388 employed wives. The data were analyzed by various statistical methods such as Frequency, Percentage, ANOVA, F-test, T-test, Pearsons' correlation analysis, Multiple Regression analysis, Path analysys. The results of this study are as follows : 1) Input variables, throughput variables, output variables had differences significantly according to the family life cycle. The employed wives' families which are former term of the family life cycle used more appropriate conflict management strategies than latter term of FLC. That is, the employed wives' families which are former term of FLC had more abundant resources such as cohesive power of family, interaction with relatives, social support, had higher planning score, used more frequent structural management strategies. But, the managerial satisfaction had no differences. 2) For the relation of input variables and throughput variables, the more resources, the lower conflict is the higher planning, implementing score, structural management score. For the relation of throughput variables, the higher planning, implementing, structural management score is the higher managerial satisfaction score. For the relation of input variables and output variables, the more resources, the lower conflict is the higher managerial satisfaction, besides objective and material resource, subjective and psychological resource had influence. 4) among all variables affecting the managerial satisfaction, the commition of housework, cohesive power of family, wives' occupational level had indirect effect on managerial satisfaction through structural managemenet. Only the income had direct effect on managerial satisfaction.

• Earthquakes and Structures
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• 제4권2호
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• pp.203-217
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• 2013

In recent decades, it has been realized that increasing the lateral stiffness of structure subjected to lateral loads is not the only parameter enhancing safety or reducing damage. Factors such as ductility and damping govern the structural response due to lateral loads. Despite the significant contribution of damping in resisting lateral loads, especially at resonance, there is no accurate mathematical representation for it. The main objective of this study is to develop a damping identification procedure for linear systems based on a mixed numerical-experimental approach, assuming viscous damping. The proposed procedure has been applied to a laboratory experiment associated with a numerical model, where a hollow rectangular steel cantilever column, having three lumped masses, has been fixed on a shaking table subjected to different exciting waves. The modal damping ratio has been identified; in addition, the effect of adding filling material to the hollow specimen has been studied in relation to damping enhancement. The results have revealed that the numerically computed response based on the identified damping is in a good fitting with the measured response. Moreover, the filling material has a significant effect in increasing the modal damping.

• 국제초고층학회논문집
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• 제2권2호
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• pp.131-139
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• 2013

The field of structural fire engineering has evolved within the construction industry, driven largely by the acceptance of performance-based or goal-based design. This evolution has brought two disciplines very close together - that of structural engineering and fire engineering. This paper presents an overview of structural systems that are frequently adopted in tall building design; typical beams and columns, concrete filled steel tube columns and long span beams with web openings. It is shown that these structural members require a structural analysis in relation to their temperature evolution and failure modes to determine adequate thermal protection for a given fire resistance period. When this is accounted for, a more explicit understanding of the behaviour of the structure and significant cost savings can be achieved. This paper demonstrates the importance of structural fire assessments in the context of tall building design. It is shown that structural engineers are more than capable of assessing structural capacity in the event of fire using published methodologies. Rather than assumed performance, this approach can result in a safe and quantified design in the event of a fire.

• 한국자동차공학회논문집
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• 제5권6호
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• pp.13-27
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• 1997

In the modern design technology, a component should be designed to fit into the overall system performance. A design methodology is developed to expedite the mechan- ical design of complex mechanical systems, The relation between the system design and component design is defined by a top-down approach and the results from the system design are utilized in the component design process. As a design example, an automobile exhaust system is selected for the system design and a bellows is chosen for a component design. Design methodology based on the top-down approach consists of five steps; (1) Analysis of service load, (2) Development of a lumped parameter, (3) Completion of the system design, (4) Selection of the component topology, (5) Completion of the component design, A method using a equivalent matrix is developed in order to determine unknown external forces in linear structural analyses. The bellows is also analyzed by the finite element method using a conical frustum shell element. Various experiments are performed to verify the developed theories. The top-down desi- gn approach is demonstrated by a design case using structural and shape optimization technology. Since the method is relatively simple and easy compared to other methods, it can be applied to the general design where system and component designs are involves simultaneously.